<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<script>
    var a = true;   //改变a 的值，查看各种转换的结果。并做好记录。
    console.log(parseInt(a));
    console.log(Number(a));
    console.log(+a);



    var a = "111";   //改变a 的值，查看各种转换的结果。并做好记录。
    console.log(parseFloat(a));
    console.log(Number(a));
    console.log(+a);


    a = 4.12;
    console.log(Math.round(4.51));//5
    console.log(Math.floor(4.12)); //4
    console.log(Math.ceil(4.12));  //5


    var x = 10;
    var y = 2;
    var z =Math.pow(10,2);  //2平方，3立方，n次方
    console.log(z);
</script>
</body>
</html>